Mount Redoubt experienced another explosive eruption on April 4, 2009, according to the Alaska Volcano Observatory. The eruption sent a cloud of volcanic ash and vapor to a height of roughly 15,240 meters (50,000 feet). The cloud drifted toward the volcano’s southeast.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite took this picture on April 4, 2009. Mount Redoubt sits on the western side of Alaska’s Cook Inlet, and the volcanic plume blows toward the southeast, across the water. On the eastern side of Cook Inlet, the plume appears to change direction, moving toward the northeast before resuming its general southeastern course. This zigzag trajectory might be explained by different wind directions at different altitudes.
On both the western and eastern sides of Cook Inlet, some of the snowy surface has been colored muddy brown, likely resulting from a coating of volcanic ash.
After keeping volcanologists waiting for weeks, Mount Redoubt erupted five times in one night, beginning on March 22, 2009. The volcano followed up with more eruptions in April, and showed continued signs of unrest in early May.